Heretofor, attache cases made of a rigid material such as aluminum alloy, plastic, etc. consist of a body, a lid hinged to the body, a handle at the middle part of the upper face of the body and a main locking mechanism for the lid. However in the conventional device, it is necessary to have the case horizontal to open the lid completely and both hands are needed for opening the case when it is vertical. If the lid is opened when the case is vertical, articles in the case may push the lid by by force of gravity to a completely open position as soon as the main locking is released causing the articles to fall out of the case.